Conventional friction pads are mostly stationary (i.e., fixedly mounted on a backing plate). After a period of time of use, an uneven surface is formed on a disc at areas contacting the friction pads when brake is being applied. This uneven surface on the disc damages the disc and hinders proper operation of the brake, especially a wave-shaped surface may be formed on the disc and when a brake is being applied, a "dead lock" may happen and the brake pedal has to be released in order to relieve the disk from the dead lock.